// Copyright 2014 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#ifndef CONTENT_COMMON_INPUT_WEB_TOUCH_EVENT_TRAITS_H_
#define CONTENT_COMMON_INPUT_WEB_TOUCH_EVENT_TRAITS_H_

#include "content/common/content_export.h"
#include "third_party/WebKit/public/platform/WebInputEvent.h"

namespace content {

// Utility class for performing operations on and with WebTouchEvents.
class CONTENT_EXPORT WebTouchEventTraits {
public:
    // Returns whether all touches in the event have the specified state.
    static bool AllTouchPointsHaveState(const blink::WebTouchEvent& event,
        blink::WebTouchPoint::State state);

    // Returns whether this event represents a transition from no active
    // touches to some active touches (the start of a new "touch sequence").
    static bool IsTouchSequenceStart(const blink::WebTouchEvent& event);

    // Returns whether this event represents a transition from active
    // touches to no active touches (the end of a "touch sequence").
    static bool IsTouchSequenceEnd(const blink::WebTouchEvent& event);

    // Sets the type of |event| to |type|, resetting any other type-specific
    // properties and updating the timestamp.
    static void ResetType(blink::WebInputEvent::Type type,
        double timestamp_sec,
        blink::WebTouchEvent* event);

    // Like ResetType but also resets the state of all active touches
    // to match the event type.  This is particularly useful, for example,
    // in sending a touchcancel for all active touches.
    static void ResetTypeAndTouchStates(blink::WebInputEvent::Type type,
        double timestamp_sec,
        blink::WebTouchEvent* event);
};

} // namespace content

#endif // CONTENT_COMMON_INPUT_WEB_TOUCH_EVENT_TRAITS_H_
